Application of BSA-bioconjugated phosphorescence nanohybrids in protein detection in biofluids

Abstract

Since the major embodiment of biofunction is proteins, research on proteins is necessary before we can reveal the rules of life activities. However, because of the compositional complexity and high background fluorescence in biological samples, the bottleneck in protein research is how to selectively recognize the target proteins. Preparation of quantum dot (QD) nanohybrids is an effective method for protein detection, and is very significant for development of QD-based protein detection techniques. In this study, a cross-linking agent 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) was used to link QDs and bovine serum albumin (BSA) to form a nanohybrid BSA–Mn-ZnS Room-Temperature Phosphorescence (RTP) biosensor. Then this sensor was used for lysozyme detection. This study expands the application scope of nanohybrids into the field of life science. After the addition of lysozyme, there were strong electrostatic interactions and other interactions between BSA and the lysozyme, which led to inter-aggregation between BSA–Mn-ZnS and lysozyme and thereby enhanced the RTP. Within a certain range, the enhancement of the RTP is proportional to the dosage of lysozyme. On this basis, a high-performance sensor for lysozyme detection was built. This sensor can be used for lysozyme detection in biofluids. The detection limit of this sensor is 0.14 nM and the detection range is 0.4–40 nM.